WATERTOWN, Mass.--(BUSINESS WIRE)--Jan. 24, 2017--
Enanta Pharmaceuticals, Inc. (NASDAQ:ENTA), a research and
development-focused biotechnology company dedicated to creating small
molecule drugs for viral infections and liver diseases, today announced
that AbbVie’s marketing authorization application (MAA) for its
investigational, pan-genotypic regimen of glecaprevir
(ABT-493)/pibrentasvir (ABT-530) (G/P) for the treatment of all major
chronic hepatitis C virus (HCV) genotypes, has been validated by the
European Medicines Agency (EMA) and is now under accelerated assessment.
If approved, G/P may provide shorter treatment duration for patients
infected with any of HCV genotypes 1-6 (GT1-6) and without cirrhosis,
who represent the majority of HCV patients. G/P is also intended to
provide an additional treatment option to patients with compensated
cirrhosis (Child Pugh A) and to address the needs of patients with
specific treatment challenges, including those with severe chronic
kidney disease (CKD) and those not cured with previous
direct-acting-antiviral (DAA) treatment.

The Committee for Medicinal Products for Human Use (CHMP), the
scientific committee of the EMA, will review the G/P regimen under
accelerated assessment, which is the EMA’s designation for new medicines
of major public health interest and therapeutic innovation, and is
designed to bring new treatments to patients more quickly. Validation of
the MAA confirms that the submission is complete and starts the EMA's
centralized review process. If approved, AbbVie's G/P regimen could
become available for marketing in the European Union (EU) in the second
half of 2017.

The MAA is supported by data from eight registrational studies in
AbbVie's G/P clinical development program, which evaluated more than
2,300 patients in 27 countries across all major HCV genotypes and
several special populations. Patient populations studied included GT1-6,
those new and experienced to treatment, those with compensated cirrhosis
and without cirrhosis, and those with specific treatment challenges,
including those with severe CKD, and those not cured with a prior
DAA-containing regimen. The program was designed to investigate a faster
path to virologic cure* for all major HCV genotypes (GT1-6) and with the
goal of addressing areas of continued unmet need.

On December 19, 2016, AbbVie announced its New Drug Application
submission for G/P to the U.S. Food and Drug Administration (FDA) for
the treatment of GT1-6 chronic HCV infection. AbbVie has also announced
that they remain on track to submit a New Drug Application for G/P in
Japan in 1Q 2017.

Glecaprevir is Enanta’s second protease inhibitor being developed
through its collaboration with AbbVie and is one of the two new
direct-acting antivirals in G/P.

G/P is an investigational product and its safety and efficacy have not
been established.

AbbVie’s glecaprevir/pibrentasvir (G/P) clinical development program was
designed to investigate a faster path to virologic cure* for all major
HCV genotypes (GT1-6) and with the goal of addressing treatment areas of
continued unmet need.

G/P is an investigational, pan-genotypic regimen being evaluated as a
potential cure in 8 weeks for HCV patients without cirrhosis and who are
new to treatment with direct-acting antivirals (DAA).**Patients with
these characteristics constitute the majority of HCV patients. AbbVie is
also studying G/P in patients with specific treatment challenges, such
as genotype 3, patients who were not cured with previous DAA treatment
and those with chronic kidney disease, including patients on dialysis.

G/P is an investigational once-daily regimen that combines two distinct
antiviral agents. G/P is a fixed-dose combination of glecaprevir
(300mg), an NS3/4A protease inhibitor, and pibrentasvir (120mg), an NS5A
inhibitor, dosed once-daily as three oral tablets.

*Patients who achieve a sustained virologic response at 12 weeks
post-treatment (SVR12) are considered cured of hepatitis C.

**Patients who are treatment-naive or not cured with previous
IFN-based treatments ([peg]IFN +/- RBV or SOF/RBV +/- pegIFN).

About Enanta

Enanta Pharmaceuticals is a research and development-focused
biotechnology company that uses its robust chemistry-driven approach and
drug discovery capabilities to create small molecule drugs for viral
infections and liver diseases. Enanta’s research and development efforts
are currently focused on three disease targets: non-alcoholic
steatohepatitis (NASH)/ primary biliary cholangitis (PBC), respiratory
syncytial virus (RSV) and hepatitis B virus (HBV).

Enanta has discovered novel protease inhibitors that are members of the
direct-acting-antiviral (DAA) inhibitor classes designed for use against
the hepatitis C virus (HCV). These protease inhibitors, developed
through Enanta’s collaboration with AbbVie, include paritaprevir, which
is contained in AbbVie’s marketed DAA regimens for HCV, and glecaprevir
(ABT-493), Enanta’s second protease inhibitor product, which AbbVie is
developing as part of an investigational, pan-genotypic, once-daily,
ribavirin-free, fixed-dose combination (G/P) with pibrentasvir
(ABT-530), AbbVie’s second NS5A inhibitor.

Enanta has discovered EDP-305, an FXR agonist product candidate for NASH
and PBC, currently in Phase 1 clinical development, and has identified a
clinical candidate for RSV, EDP-938, in preclinical development. Enanta
is also developing early lead candidates for HBV. Please visit www.enanta.com
for more information on Enanta’s programs and pipeline.

Forward Looking Statements Disclaimer

This press release contains forward-looking statements, including
statements with respect to the prospects for AbbVie’s G/P regimen in
HCV. Statements that are not historical facts are based on management’s
current expectations, estimates, forecasts and projections about
Enanta’s business and the industry in which it operates and management’s
beliefs and assumptions. The statements contained in this release are
not guarantees of future performance and involve certain risks,
uncertainties and assumptions, which are difficult to predict.
Therefore, actual outcomes and results may differ materially from what
is expressed in such forward-looking statements. Important factors and
risks that may affect actual results include: the efforts of AbbVie (our
collaborator developing glecaprevir) to obtain regulatory approvals of
its glecaprevir/pibrentasvir (G/P) combination and commercialize it
successfully; the regulatory and marketing efforts of others with
respect to competitive treatment regimens for HCV; regulatory and
reimbursement actions affecting G/P, any competitive regimen, or both;
the need to obtain and maintain patent protection for glecaprevir and
avoid potential infringement of the intellectual property rights of
others; and other risk factors described or referred to in “Risk
Factors” in Enanta’s most recent Form 10-K for the fiscal year ended
September 30, 2016 and other periodic reports filed more recently with
the Securities and Exchange Commission. Enanta cautions investors not to
place undue reliance on the forward-looking statements contained in this
release. These statements speak only as of the date of this release, and
Enanta undertakes no obligation to update or revise these statements,
except as may be required by law.